(a) Field of the Invention
This invention relates to a system for changing metal bending dies and more particularly, but not by way of limitation to an automated die transfer system for changing both male and female dies used in the bed of a press brake.
(b) Description of the Prior Art
Heretofore there have been a variety of stationary racks and wheeled carts for receiving and storing male and female press brake dies. These prior art devices provided a manual system for storing dies and receiving and transferring dies. For example, one large machine tool manufacturer offers in their press brake accessory line a die staging table designed as a push cart having grooved wheels and riding on a track for minimal operator effort. But, these manual systems do not provide for automated horizontal and automated vertical placement of the dies adjacent one end of the bed of the press brake. Also, because there is no combination of horizontal and vertical alignment of the table or cart, heavy dies often require two or more men to lift the dies onto the storage device while using a fork lift, chain hoist, and other types of heavy lifting equipment. In addition, prior art devices have not provided for a roller system capable of suspending heavy dies with low friction rollers enabling easy transport of dies on and off of the die table.
In U.S. Pat. No. 3,831,427 to Lee; U.S. Pat. No. 4,866,974 to Shiraishi et al; U.S. Pat. No. 4,680,955 to Sakamoto; and U.S. Pat. No. 4,698,894 to Lingaraju et al different types of die exchange and retention devices along with feed tables are described. None of these patents disclose a system which can service one or more press brakes for quickly and safely transferring male and female press brake dies by a single press brake operator, The subject invention eliminates the need of manhandling heavy die sets during a die change out of the press brake.